Sounds like she has self esteem issues, control problems and is going crazy. I left a job like this because higher management didn't see her craziness and she was so passive aggressive on top of it you never knew where you stood with her.

I left a job like this. Nothing worse than a control freak. She sounds nuts.

Sounds like she never outgrew doing the work herself, so now doesn't know how to manage a team. Just another bad manager...who's upsetting her team!

Dementia?

Queen bee?

The sr manager of my small group often goes on a tear and redoes various people's work or just starts doing parts of their projects and then telling them later, when she's finished. Often she won't even ask for a deliverable, she'll just do something and then later belittle the person or diminish their role on their project review.
I've seen her read entire raw data and redo a man's memo, seen her take a woman's slide deck and completely redo it, and I've seen her refuse to let me do parts of my projects so that she can "learn about it firsthand". She has also taken large accounts away from people, citing, "I need to know what's going on with these important matters firsthand." When asked she stressed it had nothing to do with anyone's ability to do their job or work quality.

What is going on here? Good people are leaving and the department head (whom she tries to control all communication with) is clueless. She wasn't like this the first couple years....